How to use the odds and probability calculator
Convert between probability, odds and percentage. Enter probability in the field above; the percentage, odds in favour, odds against are computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- p — Probability
Worked example
With probability = 0.25, the calculator gives percentage ≈ 25 %; odds in favour ≈ 0.3333333; odds against ≈ 3.
Frequently asked questions
What is the formula for the odds and probability calculation?
Percentage (%) = 100 × p. Odds in favour = p / (1-p). Odds against = (1-p) / p. Here p is probability.
What inputs do I need for the odds and probability converter calculator?
You need probability. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use this calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.